1. Field of the Invention
The present invention relates generally to lighting systems and more particularly to a distributed modular lighting control system for communicating lighting control data over the power lines.
2. Prior Art
In recent years, lighting control systems have become increasingly popular despite their usually prohibitive cost. A conventional lighting control system allows the user to remotely control a network of lighting units from a central location in a housing/office building setting. A lighting system of this type may comprise a plurality of control stations dispersed throughout the site and electrically coupled to a plurality of control modules and a programmable central control unit (CCU) which includes a central processor, holds all programming information in memory and translates button presses from control stations throughout the home into appropriate changes in lighting. The CCU is a fairly expensive component and may be provided with a modem to allow for remote system maintenance or changes to the lighting control system. The control stations are wall-mounted keypads which replace traditional light switches and dimmer controls. For example, a button on a control station may function as both a toggle and a dimmer switch and may have memory for memorizing the dimming level last used. Control modules perform the actual switching and dimming of electrical loads including dimming incandescent, low voltage, fluorescent loads, etc.
Installation of a conventional lighting control system typically requires considerable rewiring and expenditure of time and material. Data communication is typically over the power lines using various data transmission protocols. System reliability remains an issue for the conventional lighting control system even though a number of system and communication improvements have been introduced in the field over the years. For example, during data transmission, the identities of the CCU and the control modules may be confused whereby system reliability is significantly compromised.
After the lighting control system has been installed, the installer must configure and test all system components before use which is normally a relatively complicated, time-consuming and costly procedure.
Furthermore, a typical lighting control system operating over the power line may not offer a choice of carrier frequencies and/or transmitting power levels to the user. A choice of carrier frequencies is usually the first line of defense against unexpected sources of noise on the line. The user should also be able to adjust transmitting power levels depending on the line impedance of the home/office building involved.
Therefore, the need arises for an improved lighting control system for communicating lighting control data over the power line which does not use a central processor to oversee and control the operation. Such a system should preferably be implemented using a distributed system architecture, i.e. every control module having all the system programming information and processing power required to perform its function independently from the other components of the system. A distributed lighting control system of this type would substantially improve the overall system reliability, lower the system cost and provide ease of installation and maintenance for the user. Furthermore, each control module should be capable of operating on a number of carrier frequencies and transmitting power levels to be set by the user.
The present invention meets the above needs and is directed to a lighting system comprising a plurality of control modules distributed on an alternating current (AC) power line for remote control of electrical loads within a structure, each control module coupled to at least one of the electrical loads, each control module capable of independently processing and communicating data signals to the other control modules on the AC power line for control of one or a group of the electrical loads without the need for a central processor to coordinate the lighting control operation.
At least one of the plurality of control modules comprises a processor, a data decoder coupled to the processor through a data bus and means for driving a dimmer. The dimmer driving means includes a dimmer driver for generating a duty control signal for driving the dimmer through an optoisolator, the dimmer electrically coupled to the AC power line.
The lighting system further comprises means for driving the dimmer driver which includes a bridge rectifier electrically coupled to the AC power line for generating a rectified voltage signal, a potential divider coupled to the bridge rectifier for receiving the rectified voltage signal and means for generating a pulse signal for input to the dimmer driver. The pulse signal generating means includes a comparator operatively coupled to the potential divider and a resistor operatively coupled between the output of the comparator and the dimmer driver.
The lighting system further comprises means for programming at least one of the plurality of control modules. The programming means includes a programming module operatively coupled between the at least one control module and a computer for downloading system configuration data to the at least one control module through the programming module. The lighting system further comprises means for evaluating a data transmission command. The data transmission command evaluating means includes a response table downloaded to the at least one control module from the computer through the programming module for use by the processor, the response table containing an address entry for the at least one control module and a load address entry.
At least one of the plurality of control modules further comprises an application-specific integrated circuit (ASIC) coupled to the processor by way of the data bus. The ASIC includes a field-programmable gate array (FPGA), the FPGA including the dimmer driver and the data decoder.
The present invention is also directed to a lighting system comprising a plurality of control modules distributed on an alternating current (AC) power line within a structure, each control module having at least one control switch and at least one light-emitting diode (LED) operatively coupled to the at lest one control switch for status indication, each control module capable of independently processing and communicating data signals to the other control modules on the AC power line without the need for a central processor to coordinate the lighting control operation.
At least one of the plurality of control modules comprises a processor, a data decoder coupled to the processor through a data bus and a switch and LED interface operatively coupled between the at least one control switch and the at least one LED.
The lighting system further comprises means for programming at least one of the plurality of control modules. The programming means includes a programming module operatively coupled between the at least one control module and a computer for downloading system configuration data to the at least one control module through the programming module.
The lighting system further comprises means for evaluating a data transmission command. The data transmission command evaluating means includes a response table downloaded to the at least one control module from the computer through the programming module for use by the processor, the response table containing an address entry for the at least one control module, for the at least one control switch and for the at least one LED.
At least one of the plurality of control modules further comprises an application-specific integrated circuit (ASIC) coupled to the processor by way of the data bus. The ASIC includes a field-programmable gate array (FPGA), the FPGA including the switch and LED interface and the data decoder.
The present invention is further directed to a lighting system comprising a plurality of control modules distributed on an alternating current (AC) power line for remote control of electrical loads within a structure, each control module coupled to at least one of the electrical loads and having at least one control switch and at least one light-emitting diode (LED) operatively coupled to the at lest one control switch for status indication, each control module capable of independently processing and communicating data signals to the other control modules on the AC power line for control of one or a group of the electrical loads without the need for a central processor to coordinate the lighting control operation.
At least one of the plurality of control modules comprises a processor, a data decoder coupled to the processor through a data bus, a switch and LED interface operatively coupled between the at least one control switch and the at least one LED and means for driving a dimmer. The dimmer driving means includes a dimmer driver for generating a duty control signal for driving the dimmer through an optoisolator, the dimmer electrically coupled to the AC power line.
The lighting system further comprises means for driving the dimmer driver which includes a bridge rectifier electrically coupled to the AC power line for generating a rectified voltage signal, a potential divider coupled to the bridge rectifier for receiving the rectified voltage signal and means for generating a pulse signal for input to the dimmer driver. The pulse signal generating means includes a comparator operatively coupled to the potential divider and a resistor operatively coupled between the output of the comparator and the dimmer driver.
The lighting system further comprises means for programming at least one of the plurality of control modules. The programming means includes a programming module operatively coupled between the at least one control module and a computer for downloading system configuration data to the at least one control module through the programming module.
The lighting system further comprises means for evaluating a data transmission command. The data transmission command evaluating means includes a response table downloaded to the at least one control module from the computer through the programming module for use by the processor, the response table containing an address entry for the at least one control module, for the at least one control switch, for the at least one LED and a load address entry.
At least one of the plurality of control modules further comprises an application-specific integrated circuit (ASIC) coupled to the processor by way of the data bus. The ASIC includes a field-programmable gate array (FPGA), the FPGA including the dimmer driver, the data decoder and the switch and LED interface.
The present invention is still further directed to a control module for use in a lighting system distributed on an alternating current (AC) power line within a structure, the control module comprising a processor; a data decoder coupled to the processor through a data bus; a switch and light-emitting diode (LED) interface operatively coupled to the data decoder; and a dimmer driver, the control module electrically coupled to the structure wiring and capable of independently receiving and transmitting communication signals within the distributed lighting system.
In accordance with one aspect of the invention, the control module further comprises means for programming the control module. The programming means includes a programming module operatively coupled between the control module and a computer for downloading system configuration data to the control module through the programming module. The control module further comprises means for evaluating a data transmission command. The data transmission command evaluating means includes a response table downloaded to the control module from the computer through the programming module for use by the processor, the response table containing an address entry for the control module.
In accordance with another aspect of the present invention, the control module further comprises an application-specific integrated circuit (ASIC) coupled to the processor by way of the data bus. The ASIC includes a field-programmable gate array (FPGA), the FPGA including the switch and LED interface, the dimmer driver and the data decoder.
These and other aspects of the present invention will become apparent from a review of the accompanying drawings and the following detailed description of the preferred embodiments of the present invention.